Fear is the mind killer. Fear is the little death that brings total obliteration.

"I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will allow my fear to pass over me and through me. And when it has gone I will turn my inner eye to see its path. And where the fear has gone there will be nothing. Only I will remain." (From Frank Herbert's Dune)

Peter felt extreme fear when he had to - in a sweating state - click the x button on the page of his necrophilia porn and stumble across the room to put his underwear and trousers on as he heard his mum coming downstairs.